Some types of bacteria have a gene network (a quorum sensing function) that detects its own bacteria count and controls its pathogenic expression. It is known that various types of bacteria, such as opportunistic infection bacteria, use quorum sensing and collectively act to express the pathogenicity of substances such as toxins after obtaining the number of bacteria necessary to resist the defense mechanism of a host or hostile organism.
Bacterial plant diseases are known to be intractable. Most common, commercially available agents that are effective for treating plant diseases caused by mold (filamentous fungi) are not effective for treating bacterial diseases; therefore, only a limited number of agents, such as inorganic or organic copper fungicides, streptomycin, oxolinic acids, and biotic pesticides, are currently used as bacterial disease control agents. Furthermore, even when these control agents are used, a satisfactory control effect cannot always be achieved depending on the type of farm product. In recent years, the generation of oxolinic-acid-resistant Burkholderia glumae and the like has been reported. This makes the control of bacterial plant diseases even more difficult. Burkholderia glumae, which is an organism that causes bacterial plant disease, is known to use quorum sensing to discharge a burst of toxin after infecting rice, to thereby cause disease (Non-Patent Document 1).
Patent Document 1 discloses that a specific type of pyrimidinone compound can be used as a central nervous system stimulant. However, Patent Document 1: nowhere discloses the control effect of the pyrimidinone compound on bacterial plant diseases. In fact, as is clear from Test Example 1 described later, the pyrimidinone compound specifically disclosed in Patent Document 1 has absolutely no control effect on bacterial diseases.
Patent Document 2 discloses that a specific type of pyrimidinone compound has an analgesic action. However, it is silent about the control effect of the pyrimidinone compound on bacterial plant diseases.
Patent Document 3 discloses that a specific type of amide compound acts on bacteria to inhibit biofilm (biomembrane) formation. However, the document is silent about the control effect of the amide compound on bacterial plant diseases. In fact, as is clear from the Test Example described later, the amide compound of Patent Document 3 has no control effect on bacterial diseases.
Under the current situation where there is an insufficient variety of agents that are effective for controlling bacterial plant diseases, there is a strong demand for the development of an agent that effectively controls bacterial plant diseases.    Patent Document 1: Japanese Unexamined Patent Publication No. 1973-36193    Patent Document Japanese Unexamined Patent Publication No. 1979-48795    Patent Document Japanese Unexamined: Patent Publication No. 2006-512290    Non-Patent Document 1: Molecular Microbiology, (2004)